The invention relates to the production of fine fibers from attenuable materials, particularly thermoplastic materials or materials which soften upon entering a molten state as a result of the application of heat and which harden or become relatively solid upon cooling.
The method and equipment of the invention are especially suited to the formation of fibers from mineral materials such as glass and the disclosure herein accordingly describes the invention as applied to the production of glass fibers from molten glass.
Many techniques are already known for production of fibers from molten glass, some of the techniques most widely used heretofore being identified and briefly described just below.
1. Longitudinal Blowing: Other terms sometimes used include "blown fiber", "steam blown wool", "steam blown bonded mat", "low pressure air blowing", or "lengthwise jets". PA1 2. Strand: Other terms sometimes used are "continuous filament", or "textile fibers". PA1 3. Aerocor: Another term sometimes used is "flame attenuation". PA1 4. Centrifuging: Other terms sometimes used include "rotary process", "centrifugal process", "tel process", or "supertel process". PA1 1. slayter et al. U.S. Pat. No. 2,133,236 PA1 2. Slayter et al. U.S. Pat. No. 2,206,058 PA1 3. Slayter et al. U.S. Pat. No. 2,257,767 PA1 4. Slayter et al. U.S. Pat. No. 2,810,157 PA1 5. Dockerty U.S. Pat. No. 2,286,903 PA1 6. Slayter et al. U.S. Pat. No. 2,729,027 PA1 7. Day et al. U.S. Pat. No. 3,269,820 PA1 8. Stalego U.S. Pat. No. 2,489,243 PA1 9. Stalego U.S. Pat. No. 2,754,541 PA1 10. Levecque et al. U.S. Pat. No. 2,991,507 PA1 11. Levecque et al. U.S. Pat. No. 3,215,514 PA1 12. Stalego U.S. Pat. No. 2,687,551 PA1 13. Stalego U.S. Pat. No. 2,699,631 PA1 14. Karlovitz et al. U.S. Pat. No. 2,925,620 PA1 15. Karlovitz U.S. Pat. No. 2,982,991 PA1 16. Fletcher U.S. Pat. No. 2,717,416 PA1 17. Eberle U.S. Pat. No. 3,357,808 PA1 18. Paymal U.S. Pat. No. 3,634,055 PA1 19. Battigelli U.S. Pat. No. 3,649,232 PA1 20. Stalego U.S. Pat. No. 2,607,075
There are numerous variants of each of the above four processes, and some efforts in the art to combine certain of the processes. Further, there are other techniques discussed in the prior art by which prior workers have attempted to make glass fibers. However, the variants, attempted combinations, and attempted other techniques, for the most part have not met with sufficient success to achieve a separate and recognizable status in the art.
The four techniques above referred to may briefly be described as follows.